Factors Predicting HBsAg Seroclearance and Alanine Transaminase Elevation in HBeAg-Negative Hepatitis B Virus-Infected Patients with Persistently Normal Liver Function

Natural History and Hepatitis B Virus Surface Antigen (HBsAg) Spontaneous Seroclearance in Hepatitis B Virus e-Antigen (HBeAg)-Negative Patients with Inactive Chronic Infection: A Multicenter Regional Study from South Italy

Spontaneous HBsAg seroclearance has been mainly studied in populations from Asia, Australia, the Pacific Islands, and Polynesia. For the first time, we evaluated the spontaneous HBsAg seroclearance and its possible associated factors and the risk of disease progression in HBeAg-negative patients with inactive infection all coming from the same region in South Italy. In this multicenter retrospective study, 146 patients were selected after 18 months of observation and followed for a median of 82 months (IQR 60-107). For our analyses, they were divided into three groups based on their HBsAg levels: <100 IU/mL, 100-1000 IU/mL, and >1000 IU/mL. Crude and adjusted hazard ratios (HRs) for HBsAg seroclearance were determined. During the follow-up period, three patients (2.0%) showed a disease progression with an increased liver stiffness, whereas 17 (11.6%) cleared the HBsAg. Patients with HBsAg levels <100 IU/mL had the highest probability of HBsAg seroclearance compared to the other two groups (p = 0.009). In the multivariate analysis, the HBsAg level <100 IU/mL was the only parameter independently associated with HBsAg seroclearance (adjusted HR = 3.53; CI 1.29-9.69; p = 0.01). In patients with chronic HBV inactive infection, HBsAg levels <100 IU/mL predicted the highest probability of HBsAg seroclearance.

Spontaneous loss of surface antigen among adults living with chronic hepatitis B virus infection: a systematic review and pooled meta-analyses

BACKGROUND

Spontaneous loss of HBsAg (known as functional cure) in patients with chronic hepatitis B virus (HBV) infection significantly reduces liver-related complications. HBsAg loss has been suggested to be higher in non-endemic regions than in endemic regions in individual studies. We systematically determined a pooled annual rate of HBsAg loss in adults with untreated chronic HBV infection and examined the effect of regional endemicity.

METHODS

In this systematic review and meta-analysis, we searched PubMed and Embase for observational cohort studies and non-treatment arms of randomised controlled trials reporting proportions of patients with chronic HBV infection that achieved spontaneous HBsAg loss, published up to Oct 1, 2018. We excluded randomised controlled trials from meta-analyses because of substantial cohort differences. Two reviewers (KZ and CC) independently extracted data from accepted full-text studies, with discrepancies discussed with a third reviewer (NT). We assessed rate of HBsAg loss, and stratified results by whether the underlying cohort arose primarily from an endemic region (defined as having prevalence of chronic HBV greater than 2%) or non-endemic region. This study is registered with PROSPERO, number CRD42018074086.

FINDINGS

Of 5186 studies screened, 67 (11 randomised controlled trials, 39 prospective and 17 retrospective cohort studies) met the inclusion criteria and 56 were included in meta-analyses after exclusion of randomised controlled trials. Spontaneous HBsAg loss occurred in 3837 (7·8%) of 48 972 patients, with cumulative 352 381 person-years of follow-up. The pooled annual incidence of HBsAg loss was 1·17% (95% CI 0·94-1·41, I²=97%). Rates did not differ by endemicity: 1·19% (0·88-1·54) in endemic versus 1·29% (0·99-1·62) in non-endemic cohorts.

INTERPRETATION

Globally, spontaneous HBsAg loss occurs infrequently (about 1% per year) in treatment-naive adults with chronic HBV infection. The low and homogeneous rate of HBsAg loss highlights the need for new therapeutics aimed at achieving functional cure across different patient groups and geographical regions.

FUNDING

NIH National Institute of Diabetes and Digestive and Kidney Diseases.